How good is normal visual acuity?. A study of letter acuity thresholds as a function of age

Albrecht Von Graefes Arch Klin Exp Ophthalmol. 1981;215(3):149-57. doi: 10.1007/BF00413146.


Visual acuity levels were studied in 100 normal subjects of different ages, using a finely graduated letter chart under carefully optimized test conditions. Each line on the chart contained 10 letters of similar difficulty, arranged in random order. A statistical analysis of different response criteria showed a clear superiority of fractional criteria (e.g. 50% correct responses) over the traditional 100% correct requirement. The average difference between right and left eyes was 0.04 +/- 0.15 (decimal notation). Regression analysis of the dependence of visual acuity on age showed a monotonic rise towards the age of 25 years, and a gradual decline thereafter. The most marked decline occurred after the age of 60. Age-dependent confidence intervals were tabulated. The results indicate that minor modifications of the conventional test procedure can enhance the diagnostic potential considerably.

MeSH terms

  • Adolescent
  • Adult
  • Aged
  • Aging
  • Child
  • Female
  • Humans
  • Male
  • Middle Aged
  • Sensory Thresholds
  • Vision Tests
  • Visual Acuity*